Ammonium nitrate with timer devices were used in the IEDs in Mumbai, said the home minister.
Death toll in the Mumbai blasts is 18 including that of a severed head which is yet to be identified, said Chidambaram. According to the home minister, 131 have been admitted to 13 hospitals, of which 26 have been discharged and 82 have been said to be stable. Of the 131, 23 are critically injured.
Blasts sites have been cordoned off; people will not be allowed there.
"All groups that are capable of carrying out such attacks are suspects. No intelligence inputs about yesterday's blast with Central and state agencies," said Chidambaram.
"I am sad that the second incident of terror attack has happened after 26/11 carnage and both have happened in Maharashtra," added Chidambaram.
Chidambaram rejected suggestions that there was an intelligence failure. "Blasts not aimed at hitting markets, the terror group chose targets with high population density," he said."We have made it clear to Maharashtra Police not to rule out any angle. We will probe every hostile group. We are not ruling out anything," he said.
Possibility of derailing the Indo-Pak talks by carrying out the blasts also not ruled out. "We live in the most troubled neighbourhood. Pakistan and Afghanistan are the epicentres of terrorism," said Chidambaram.